The present invention relates to a biomass producing system and in particular to a floating nitrification reactor in a treatment system.
For many years, fixed film reactors, or trickle filters, have been a widely applied method for the biological oxidation of organic waste. Biologic growths on the reactor's surface converts dissolved organic waste material or ammonia nitrogen into stable byproducts including carbon dioxide, nitrates, nitrites, water, and biological solids. These byproducts are later removed. Thus, the fixed film reactor is a cost efficient method for biochemical oxygen demand (BOD) reduction, nitrification, denitrification, odor scrubbing, and anaerobic treatment.
Nitrification reactors normally consist of a separate structure within the biomass producing system. The nitrification reactor structure is a tall tower of material, such as conventional modular sheet media. The sheet media is housed in a building wherein the sheet media goes from wall-to-wall covering the entire surface area within the building. Some towers reach heights of 50 feet.
For proper nitrification, both air and water must penetrate a given surface of the sheet media. During operation, water is pumped along the outside of the housing to the top of the tower and is then trickled down through the modular sheet media. Thus, wherever water trickles down and comes in contact with both oxygen and the sheet media, the nitrification process occurs.
Because of their size, nitrification towers are very expensive to build and maintain. It is also expensive and inefficient to continuously pump water to the top of the towers, thereby allowing the water to trickle down through the sheet media.
Submerged nitrification reactors have previously been built in the United States. To realize maximum oxidation of organic wastes in a submerged nitrification reactor, a constant air pressure is critical. Constant air pressure within a submerged reactor is obtained when the source of oxygen within the reactor is kept at a constant distance below the water level.
One known submerged nitrification system incorporates a submerged tank into the treatment process. Sheet media within the submerged tank extends from wall-to-wall of the tank for bacterial attachment. Wastewater is channeled into the tank and maintained at a constant level throughout the nitrification process. Air is bubbled-up through the sheet media from aerators or jets affixed to the floor of the tank. Since the water level within the tank remains constant, constant air pressure is maintained. This type of submerged nitrification system requires both a separate tank within the oxidation process and a constant water level within the tank. The maintenance of these requirements are expensive and inefficient.
Another known submerged nitrification system also requires the use of a submerged tank within the treatment process. This system also channels wastewater into the tank and utilizes aerators or jets affixed to the bottom of the tank. However, this system incorporates the use of small sponges or foam-like particles floating about the tank for bacterial attachment. This type of nitrification system, like the previously described system, is both expensive to maintain and inefficient.
The present invention addresses these and other problems related to nitrification reactors in a treatment system.